To retrieve all images acquired by the camera, call the function SIDXAcquisitionFramesAvailable to find out if there are images available. Once the function reports that there are images available, the images should be read out before the next call to SIDXAcquisitionFramesAvailable is made. Otherwise the images reported from the previous SIDXAcquisitionFramesAvailable call will be lost.
"readout" is used to describe how the camera builds up the pixel data of an image. A "track" is a banded region on the CCD. It has a certain height (less than or equal to the CCD height) but always has the full CCD width. In the multi-track mode, the user may specify one or multiple tracks. Each track results in a net single charge per column. There are several ways to divid the CCD into bands: a) full CCD is one band, b) a single band located anywhere on the CCD, c) multiple bands evenly spaced, and d) multiple bands located anywhere on the CCD but without overlapping. Any Andor camera may have one or more of the capabilities. In order to run the camera in multi-track readout mode, the readout mode of the camera should be set to multi-track readout mode using SIDXSettingSet with tag value of "AndorReadoutMode".
A "single scan" is one exposure of the CCD chip. It results in a set of pixel data under the given exposure time. When the accumulation count is one, a "single scan" results in one image. When the accumulation count is more than one, the resulting image is the sum of more than one scan. Andor cameras have a built-in mode which allows you to capture a sequence of single scans or accumulated scans with specified delay. Andor names the mode "Kinetic series" mode. In the mode, you will be able to control the following parameters:
Please notice that the time between every "single scan" has to be greater than the exposure time specified by SIDXExposureTimeGet/SIDXExposureTimeSet and the delay of each image has to be equal to or greater than the time taken to form one image.
The time to complete one scan varies, depending on the ROI and binning settings. In other words, if the ROI decreases and binning settings increase, the resulting pixel count of one scan is smaller and the time needed for getting one scan decreases. As a result, the minimum kinetic cycle time (the minimum time between each image) changes. SIDX invalidates and resets the timing parameters if they become invalid when ROI and/or binning settings are changed (during the function SIDXROISet or SIDXBinningSet). The timing parameters will be set to run the camera at the fastest possible rate given the ROI and binning settings.
SIDX supports this mode through the sequential acqusition which begins with the function SIDXAcquisitionBeginSequence. The focus and continuous mode in SIDX do not support the "kinetic series" mode. The accumulated count in SIDX focus and continuous mode is always one. When "track" readout mode is selected, the camera will not run in "kinetic series" mode.
If you are looking for getting the fastest possible frame rate from your Andor camera, you may want to use the "fast kinetic acquisition" mode. In this mode, the camera takes a certain number of images, and stores them on the camera rather than in the computer. After taking all the images, the camera reads the images out into the computer. As the result, it eliminates the readout time spent between each exposure in order to speed up the frame rate.
SIDX supports this mode in the acquisition sequence beginning with the function SIDXAcquisitionBeginSequence. You will have to make sure that all images will fit into the CCD. For example, 64 discrete images can be stored using a CCD-chip with a height of 512 pixels and a sub area 8 rows high. Please notice that there are sometimes certain areas on the CCD-chip cannot be used for storing. Please check with the camera specification or with the camera vendor for details.
An Andor camera may have multiple ADC channels. Each of the ADC channels may have multiple types of amplifiers. Each of the amplifiers may have multiple horizontal speed choices. Each speed choice has its own pre-amplifier. For an amplifier, the user may or may not be able to control the gain. For example, if a camera supports the EM gain, the EM gain can be turned on and off. When it is on, the EM gain can adjusted. When it is off, readout is completed by passing the electron multiplier gain using the conventional gain, which is not controllable by the user.
When setting and retrieving a gain value (For example, EM gain, or pre-amplifier gain) using SIDXSettingSet and SIDXSettingGet, the gain value setting/getting is always for the current settings. For example, when setting/getting a pre-amplifier gain using SIDXSettingSet/SIDXSettingGet, the pre-amplifier gain is for the current selected ADC channel, amplifier, speed choice, and pre-amplifier.
The available gain types in Andor cameras:
With iXon cameras, the shutter should be given sufficient time (~100ms) to open before it is closed again. If less time is given, the image will be distorted as the shutter will not be fully open. If this is done repeatedly, the shutter may be destroyed.
This trigger mode is only available in EM Newton cameras. The frame rate is higher than in the normal external trigger mode, but the EM rate is lower. It is useful only when you still want to improve the frame rate in full vertical binning mode in EM Newton camera.
This feature is not supported currently in SIDX.
Photon counting is only availabe in iStar and iXon cameras (see Andor camera specification for more details). Photon counting counts the number of times the signal level for a particular pixel is between the low and high threshold level. If there are 500 scans in the accumulation and a particular pixel is counted within the threshold 100 times, the photon counting value for the pixel will be 100.
The photon counting is only available in the sequential acquisition mode, the acquisition started with SIDXAcquisitionBeginSequence when not running in fast kinetic series acqusition mode.